The purpose of this study is to evaluate combination immunotherapy of interleukin-2 (IL-2) plus the diganglioside (GD-2) reactive chimeric monoclonal antibody (ch14.18) in adults with malignant melanoma. The addition of GD-2 reactive ch14.18 monoclonal antibody to IL-2-activated effector cells allows for antibody-dependent cellular cytotoxicity (ADCC) and augmented in vitro lysis of GD-2-positive neuroblastoma and melanoma cells. This protocol will attempt to obtain clinically significant in vivo ADCC.